It's a bit if a dilemma isn't it? Everyone thinks top footballers earn an obscene amount of money and a lot of that money would be better kept within the game through, as you say, more investment in grass roots football.
But we all know that isn't the rationale behind it. It is to stop teams making the most money hoovering up the best players. Not a bad motivation, per se. But where do these teams making the most money get it from? From being successful in competitions that give huge rewards to the few clubs participating. So what do we want? Huge rewards with a salary cap and more money to grass roots football? Or less rewards for participating, with more money going to grass roots football at source without the need for a salary cap (especially given that now total salary costs are capped as a % of revenues anyway).
I am pretty sure the big clubs don't want the latter, and understandably so from their point of view, but from a neutral's or a fan's point of view, and possibly a legal point of view, surely it is the better solution?